Mesoscopic persistent currents in a strong magnetic field

TL;DR

This paper extends the theory of mesoscopic persistent currents to account for finite ring thickness and magnetic field penetration, analyzing how these factors influence current measurements and electron interactions.

Contribution

It introduces a theoretical framework incorporating finite thickness effects and magnetic field penetration in mesoscopic persistent currents, aligning with recent experimental techniques.

Findings

Magnetic field suppresses interaction-induced persistent currents.

Technique enables measurement of the full distribution of persistent currents.

Theoretical results agree quantitatively with experimental data.

Abstract

Recent precision measurements of mesoscopic persistent currents in normal-metal rings rely on the interaction between the magnetic moment generated by the current and a large applied magnetic field. Motivated by this technique, we extend the theory of mesoscopic persistent currents to include the effect of the finite thickness of the ring and the resulting penetration of the large magnetic field. We discuss both the sample-specific typical current and the ensemble-averaged current which is dominated by the effects of electron-electron interactions. We find that the magnetic field strongly suppresses the interaction-induced persistent current and so provides direct access to the independent-electron contribution. Moreover, the technique allows for measurements of the entire distribution function of the persistent current. We also discuss the consequences of the Zeeman splitting and spin-orbit scattering, and include a detailed and quantitative comparison of our theoretical results to experimental data.